FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE
Specification
(Section 10; rule 13)
A SPLIT AIR CONDITIONING SYSTEM
VIDEOCON INTERNATIONAL LIMITED
of Auto Cars Compound, Adalat Road, Aurangabad 431 005, Maharashtra, India,
an Indian Company
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED:-

This invention relates to air conditioners and typically to air conditioners known as split air conditioners having an indoor unit and an outdoor unit cooperating with each other via ducting and piping.
A major concern in air conditioning system is the running cost and there is constant endeavor to conserve energy.
Air Conditioners can be broadly termed as devices which facilitate heat exchange from/to a closed environment/space.
Traditionally low tonnage systems are air-cooled and high tonnage systems are water-cooled.
The typical working of an air conditioner is as follows: An air conditioner has an evaporator unit and a condenser unit. In a split type air conditioner, typically the indoor unit houses the evaporator coils whereas the outdoor unit houses the condenser and the compressor. When an air conditioner is started high pressure & high temperature refrigerant is discharged from the compressor in the evaporator side . (Pressure=290 PSI & temp=90 deg). This refrigerant then passes through the typically copper tubes of the condenser coil of the condenser unit in the outdoor unit. Air is continuously blown over the condenser coil & generally finned aluminum surface bonded with the copper tubes. This cools down the refrigerant to typically 50 degrees Celsius & pressures typically at 270 PSI. The refrigerant then passes through capillary Tube (expansion device). When it comes out of capillary it expands & due to expansion there is sudden pressure drop, which also results in drop in temperature of the refrigerant. This low pressure, & low
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temperature refrigerant flows through an evaporator coil located in a room or other environment which needs to be conditioned. A blower associated with the indoor unit sucks air from the environment in a room in which the air conditioner is installed & while passing over the evaporator coil the air cools down and is circulated back to the room environment thus the heat of the air is absorbed by the refrigerant & the cool air is circulated in the room. Because of the low temperature surface of evaporator coil, the moisture present in the air condenses on the evaporator coil surface & this moisture is drained out in the form of water droplets via a water drain attached to the evaporator coil in the indoor unit. Thus dehumidification process takes place. The refrigerant is then sucked by the compressor & this cycle continues.
In the case of low tonnage systems in split air conditioners a Reciprocating/ Rotary/scroll Compressor is used, typically where the Pressure of Suction and Discharge is in equilibrium at 75 psi [pounds per square inch] suction pressure and 300 psi discharge pressure.
In these air cooled system a blower fan typically blows ambient air through the coils which are typically straight or 'L' shaped. The relative difference in the temperatures between the ambient and the compressed refrigerant causes the refreigerant to cool down.
For the Refrigerant R-22 the ideal performance is derived at 69/215 psi suction/discharge pressure which is not achievable in air cooled systems.
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For the Refrigerant R-22 the ideal performance is derived at 69/215 psi suction/discharge pressure which is not achievable in air cooled systems.
An object of this invention is to provide an air conditioning system which will give a suction pressure of 65 to 70 psi and discharge pressure of 210 -225 psi.
Such a system if engineered would be more efficient than the traditional systems and also provide saving in energy consumption.
Another object of this invention is to provide an air conditioning system in which there is considerable power conservation.
According to this invention there is provided a split air conditioning system consisting of an indoor evaporator unit having a water drain extending from the evaporator coil and an outdoor condenser unit including a compressor and a condenser coil, characterized in that the condenser coil is a hollow bodied and D or O shaped and a fan operating in suction mode is axially placed operatively on or near the top of the coil.
The objects of this invention are achieved in accordance with another aspect of this invention by using a hollow bodied coil, typically D or O shaped in the condenser unit and locating the fan approximately axially and at a location above or near the top of the coil.
Operating the fan in suction mode will cause air to be sucked in through the base and the sides of the coil and the air dynamics follows a natural
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convention current path. In accordance with the system of this invention there is significant increase of air displaced through the condenser coils per unit time and there is also increased contact between the displaced air and the coils and fins.
In accordance with a practical embodiment of this invention the hollow bodied coil is used which is made with .3/8 inch single row tubes with 16FPI PCM Aluminum fins.
The invention will now be described with reference to the accompanying drawings, in which
Figure 1 is a general lay out of a conventional split air conditioning system; Figure 2 is a lay out of the split air conditioning system in accordance with
this invention; and Figure 3 shows a plan view of the system shown in figure 2.
Referring to the drawings, a split air conditioning unit is generally indicated by the reference numeral 10. The split air conditioning system 10 consists of an indoor evaporator unit 12 having a water drain 14 extending from the evaporator coil [not shown] and an outdoor unit 16 including a compressor [not shown] and a condenser coil 18. The outdoor unit also includes a fan 20. In the operative configuration of the fan 20, air is sucked in through the coil 18 which cools the refrigerant passing through the coil. Refrigerant in fluid form flows via conduits 21 between the indoor unit 12 and the outdoor unit 16.
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The split air conditioning system 100 according to this invention is illustrated in figures 2 and 3. As seen in figure 2 and particularly in figure 3 in the plan view the condenser unit 118 located in the outdoor unit generally indicated by reference numeral 116, is a hollow bodied condenser which is a D or O shaped hollow bodied coil and the fan 120 is located roughly axially above or near the top of the coil 118. A plan of the arrangement is seen in figure 3 . Reference numeral 121 represent the refrigerant tube system and 114 is the conventional drain
Operating the fan 120 in suction mode will cause air to be sucked in through the base and the sides of the coil 118 and the air dynamics follows a natural convention current path. In accordance with the system of this invention there is significant increase of air displaced through the condenser coils per unit time and there is also increased contact between the displaced air and the coil tubes 126 and fins 124.
The results obtainable from using the features of this invention at conditions of 35 degrees Celsius ambient are typically as under :
1. SUCTION PRESSURE 65 PSI
2. DISCHARGE PRESSURE 240 PSI
3. COMPRESSOR CURRENT 6.5 A AGAINST STD 9.5 A
4. TOTAL CURRENT OF SYSTEM 8A
5. TOTAL SYSTEM WATTAGE 1650 AGAINST 1950 STD
6. TRIP RATIO( COMPRESSOR ON TIME 55% AGAINST 60% STD
The system of this invention saves over 20% in power consumption.
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While the present invention has been described herein with
reference to a specific embodiment thereof, it is contemplated
that the present invention is not limited thereby and various
changes and modifications may be made therein for those
skilled in the art without departing from the scope of the
invention
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We Claim:
1. A split air conditioning system consisting of an indoor evaporator unit having a water drain extending from the evaporator coil and an outdoor condenser unit including a compressor and a condenser coil, characterized in that the condenser coil is hollow bodied and D or O shaped and a fan operating in suction mode is axially placed operatively on or near the top of the coil.
2. A split air conditioning system as claimed in claim 1, in which hollow bodied coil is made with single row tubes with fins, typically of aluminum.
3. A split air conditioning system as described herein with reference to the accompanying drawings.

of R K Dewan & Co Applicants' Patent Attorney
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Dated this 27th day August, 2003